Karl Lundgren shot Joe Brody four times , then two shots at Philip Marlowe just outside of Joe Brodys flat and then continue to shoot while running away. Thats too many shot for a standard 6 shot revolver.
When Marlowe brings Camilla home from Geiger's house, the shot from the car to the Sternwood's door shows Marlowe's car door open. The reverse shot from the house out to the car shows his car door shut.
In the night of Geigers murder, Marlowe returns to Geigers home in a Taxi (20:18) with a numberplate 7077. Next day Marlowe follows a truck from Geigers shop (25:26) in a taxi with the same plate 7077 after stopping the taxi in the street.